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Supplementary Table 1 from A Novel Derivative of the Natural Agent Deguelin for Cancer Chemoprevention and Therapy

The natural compound deguelin has promising preventive and therapeutic activity against diverse cancers by directly binding to heat shock protein-90 and thus suppressing its function. Potential side effects of deguelin over a certain dose, however, could be a substantial obstacle to its clinical use. To develop a derivative(s) of deguelin with reduced potential side effects, we synthesized five deguelin analogues (SH-02, SH-03, SH-09, SH-14, and SH-15) and compared them with the parent compound and each other for structural and biochemical features; solubility; and antiproliferative effects on normal, premalignant, and malignant human bronchial epithelial (HBE) and non–small-cell lung cancer (NSCLC) cell lines. Four derivatives destabilized hypoxia-inducible factor-1α as potently as did deguelin. Reverse-phase protein array (RPPA) analysis in H460 NSCLC cells revealed that deguelin and the derivatives suppressed expression of a number of proteins including heat shock protein-90 clients and proteins involved in the phosphoinositide 3-kinase/Akt pathway. One derivative, SH-14, showed several features of potential superiority for clinical use: the highest apoptotic activity; no detectable influence on Src/signal transducer and activator of transcription signaling, which can promote cancer progression and is closely related to pathogenesis of Parkinson's disease (deguelin, SH-02 and SH-03 strongly activated this signaling); better aqueous solubility; and less cytotoxicity to immortalized HBE cells (versus deguelin) at a dose (1 μmol/L) that induced apoptotic activity in most premalignant and malignant HBE and NSCLC cell lines. These collective results suggest that the novel derivative SH-14 has strong potential for cancer chemoprevention and therapy, with equivalent efficacy and lesser toxicity (versus deguelin).

Ligand-targeted drugs (LTDs) such as antibody-drug conjugates (ADCs) are currently attracting great attention as an alternative class of therapeutics to conventional chemotherapy for the clinical treatment of cancer. The linker is one of important factors determining the efficacy and toxicity of LTDs. The linker for LTDs should have enough stability during blood circulation, effectively release the payload, and leave no polar moieties in the released payload. However, the drug release activity and plasma stability of cleavable linkers are generally evaluated by complex and sophisticated

Imatinib (Gleevec) is a multiple tyrosine kinase inhibitor that decreases the activity of the fusion oncogene called BCR-ABL (breakpoint cluster region protein-Abelson murine leukemia viral oncogene homolog) and is clinically used for the treatment of chronic myelogenous leukemia and acute lymphocytic leukemia. Small molecule drugs, such as imatinib, can bind to several cellular proteins including the target proteins in the cells, inducing undesirable effects along with the effects against the disease. In this study, we report the synthetic optimization for 14 C-labeling and radiosynthesis of [14 C]imatinib to analyze binding with cellular proteins using accelerator mass spectroscopy. 14 C-labeling of imatinib was performed by the synthesis of 14 C-labeld 2-aminopyrimidine intermediate using [14 C]guanidine·HCl, which includes an in situ reduction of an inseparable byproduct for easy purification by HPLC, followed by a cross-coupling reaction with aryl bromide precursor. The radiosynthesis of [14 C]imatinib (specific activity, 631 MBq/mmol; radiochemical purity, 99.6%) was achieved in six steps with a total chemical yield of 29.2%.

Lichens are a life form in which algae and fungi have a symbiotic relationship and have various biological activities, including anti-inflammatory and antiproliferative activities. This is the first study to investigate the anti-inflammatory activity of a

Heat-shock protein 90 (HSP90) is a molecular chaperone that activates oncogenic transformation in several solid tumors, including lung and breast cancers. Ganetespib, a most promising candidate among several HSP90 inhibitors under clinical trials, has entered Phase III clinical trials for cancer therapy. Despite numerous evidences validating HSP90 as a target of anticancer, there are few studies on PET agents targeting oncogenic HSP90. In this study, we synthesized and biologically evaluated a novel 18F-labeled 5-resorcinolic triazolone derivative (1, [18F]PTP-Ganetespib) based on ganetespib. [18F]PTP-Ganetespib was labeled by click chemistry of Ganetespib-PEG-Alkyne (10) and [18F]PEG-N3 (11) with 37.3 ± 5.11% of radiochemical yield and 99.7 ± 0.09% of radiochemical purity. [18F]PTP-Ganetespib showed proper LogP (0.96 ± 0.06) and good stability in human serum over 97% for 2 h. [18F]PTP-Ganetespib showed high uptakes in breast cancer cells containing triple negative breast cancer (TNBC) MDA-MB-231 and Her2-negative MCF-7 cells, which are target breast cancer cell lines of HSP90 inhibitor, ganetespib, as an anticancer. Blocking of HSP90 by the pretreatment of ganetespib exhibited significantly decreased accumulation of [18F]PTP-Ganetespib in MDA-MB-231 and MCF-7 cells, indicating the specific binding of [18F]PTP-Ganetespib to MDA-MB-231 and MCF-7 cells with high HSP90 expression. In the biodistribution and microPET imaging studies, the initial uptake into tumor was weaker than in other thoracic and abdominal organs, but [18F]PTP-Ganetespib was retained relatively longer in the tumor than other organs. The uptake of [18F]PTP-Ganetespib in tumors was not sufficient for further development as a tumor-specific PET imaging agent by itself, but this preliminary PET imaging study of [18F]PTP-Ganetespib can be basis for developing new PET imaging agents based on HSP90 inhibitor, ganetespib.

The chemical modification of amino acids plays an important role in the modulation of proteins or peptides and has useful applications in the activation and stabilization of enzymes, chemical biology, shotgun proteomics, and the production of peptide-based drugs. Although chemoselective modification of amino acids such as lysine and arginine via the insertion of respective chemical moieties as citraconic anhydride and phenyl glyoxal is important for achieving desired application objectives and has been extensively reported, the extent and chemoselectivity of the chemical modification of specific amino acids using specific chemical agents (blocking or modifying agents) has yet to be sufficiently clarified owing to a lack of suitable assay methodologies. In this study, we examined the utility of a fluorogenic assay method, based on a fluorogenic tripeptide substrate (FP-AA1-AA2-AA3) and the proteolytic enzyme trypsin, in determinations of the extent and chemoselectivity of the chemical modification of lysine or arginine. As substrates, we used two fluorogenic tripeptide probes, MeRho-Lys-Gly-Leu(Ac) (lysine-specific substrate) and MeRho-Arg-Gly-Leu(Ac) (arginine-specific substrate), which were designed, synthesized, and evaluated for chemoselective modification of specific amino acids (lysine and arginine) using the fluorogenic assay. The results are summarized in terms of half-maximal inhibitory concentrations (IC50) for the extent of modification and ratios of IC50 values (IC50arginine/IC50lysine and IC50lysine/IC50arginine) as a measure of the chemoselectivity of chemical modification for amino acids lysine and arginine. This novel fluorogenic assay was found to be rapid, precise, and reproducible for determinations of the extent and chemoselectivity of chemical modification.

Physconia hokkaidensis methanol extract (PHE) was studied to identify anticancer effects and reveal its mechanism of action by an analysis of cytotoxicity, cell cycles, and apoptosis biomarkers. PHE showed strong cytotoxicity in various cancer cells, including HL-60, HeLa, A549, Hep G2, AGS, MDA-MB-231, and MCF-7. Of these cell lines, the growth of MDA-MB-231 was concentration-dependently suppressed by PHE, but MCF-7 was not affected. MDA-MB-231 cells, triple-negative breast cancer (TNBC) cells, do not express estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER-2), whereas MCF-7 cells are ER-positive, PR-positive, and HER-2-negative breast cancer cells. The number of cells in sub-G1 phase was increased after 24 h of treatment, and annexin V/PI staining showed that the population size of apoptotic cells was increased by prolonged exposure to PHE. Moreover, PHE treatment downregulated the transcriptional levels of Bcl-2, AMPK, and p-Akt, whereas it significantly upregulated the levels of cleaved caspase-3, cleaved caspase-9, and cleaved-PARP. In conclusion, it was confirmed that the PHE exhibited selective cytotoxicity toward MDA-MB-231, not toward MCF-7, and its cytotoxic activity is based on induction of apoptosis.

The selectivity of a drug toward various isoforms of the target protein family is important in terms of toxicology. Typically, drug or candidate selectivity is assessed by in vitro assays, but in vivo investigations are currently lacking. Positron emission tomography (PET) allows the non-invasive determination of the in vivo distribution of a radiolabeled drug, which can provide in vivo data regarding drug selectivity. Since the discovery of propranolol, a non-selective β-blocker inhibiting both β

Lichens, composite organisms resulting from the symbiotic association between the fungi and algae, produce a variety of secondary metabolites that exhibit pharmacological activities. This study aimed to investigate the anti-inflammatory activities of the secondary metabolite atraric acid produced by Heterodermia hypoleuca. The results confirmed that atraric acid could regulate induced pro-inflammatory cytokine, nitric oxide, prostaglandin E2, induced nitric oxide synthase and cyclooxygenase-2 enzyme expression in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Meanwhile, atraric acid downregulated the expression of phosphorylated I&kappa, B, extracellular signal-regulated kinases (ERK) and nuclear factor kappa B (NF&kappa, B) signaling pathway to exhibit anti-inflammatory effects in LPS-stimulated RAW264.7 cells. Based on these results, the anti-inflammatory effect of atraric acid during LPS-induced endotoxin shock in a mouse model was confirmed. In the atraric acid treated-group, cytokine production was decreased in the peritoneum and serum, and each organ damaged by LPS-stimulation was recovered. These results indicate that atraric acid has an anti-inflammatory effect, which may be the underlying molecular mechanism involved in the inactivation of the ERK/NF&kappa, B signaling pathway, demonstrating its potential therapeutic value for treating inflammatory diseases.

Correction for ‘A preliminary study for the development of cleavable linkers using activatable fluorescent probes targeting leucine aminopeptidase’ by Julie Kang et al., Analyst, 2022, https://doi.org/10.1039/d2an01145j.

Hypoxia is a common feature of many solid tumors and is known to cause the resistance to chemotherapy and radiotherapy. Nitroreductase (NTR), a common biomarker of hypoxia, is an attractive target for the design of therapeutics and imaging agents targeting hypoxia. Under hypoxic condition, nitroreductase can reduce an aromatic nitro group conjugated to a drug or fluorophore to amine, which leads to release a free drug or fluorophore through the subsequent 1,6-rearrangment elimination. This type of 1,6-rearrangement elimination to release a drug or fluorophore has been widely used in the development of activity-based “turn on” fluorescent probes as well as targeted therapeutics such as antibody-drug conjugates (ADCs) and small molecule-drug conjugates (SMDCs). In this paper, novel “turn on” NTR-responsive fluorescent probes diversely linked to a 4-nitrobenzyl moiety via ether, carbonate, amine and carbamate linkages have been developed. The effect of variation in linkage on the release of fluorophore has been studied by the analysis of spectroscopic properties, temperature and pH stability, kinetics and concentration-dependency of the probes during NTR reaction. Fluorescent probes with an ether (10) or a carbamate (16) linkage showed biocompatible nature, high sensitivity (working below 1 μM of concentration) and strong fluorescence emission in the presence of NTR whereas they showed very low quantum yields in the absence of NTR. Finally, the probes (10, 16) were successfully applied to in vitro imaging of hypoxic cancer cells.

Carbonic anhydrase IX is overexpressed in many solid tumors including hypoxic tumors and is a potential target for cancer therapy and diagnosis. Reported imaging agents targeting CA-IX are successful mostly in clear cell renal carcinoma as SKRC-52 and no candidate was approved yet in clinical trials for imaging of CA-IX. To validate CA-IX as a valid target for imaging of hypoxic tumor, we designed and synthesized novel [18F]-PET tracer (1) based on acetazolamide which is one of the well-known CA-IX inhibitors and performed imaging study in CA-IX expressing hypoxic tumor model as 4T1 and HT-29 in vivo models other than SKRC-52. [18F]-acetazolamide (1) was found to be insufficient for the specific accumulation in CA-IX expressing tumor. This study might be useful to understand in vivo behavior of acetazolamide PET tracer and can contribute to the development of successful PET imaging agents targeting CA-IX in future. Additional study is needed to understand the mechanism of poor targeting of CA-IX, as if CA-IX is not reliable as a sole target for imaging of CA-IX expressing hypoxic solid tumors.

The selectivity of a drug toward various isoforms of the target protein family is important in terms of toxicology. Typically, drug or candidate selectivity is assessed by in vitro assays, but in vivo investigations are currently lacking. Positron emission tomography (PET) allows the non-invasive determination of the in vivo distribution of a radiolabeled drug, which can provide in vivo data regarding drug selectivity. Since the discovery of propranolol, a non-selective β-blocker inhibiting both β1- and β2-adrenoreceptors (β-ARs), various selective β1-blockers, including bisoprolol, have been developed to overcome disadvantages associated with β2-AR inhibition. As a proof of concept, we performed an in vivo PET study to understand the selectivity and efficacy of bisoprolol as a selective β-blocker toward β1-AR, as the heart and peripheral smooth muscles demonstrate distinct populations of β1- and β2-ARs. Biodistribution of 18F-labeled bisoprolol (1, [18F]bisoprolol) showed the retention of its uptake in the heart compared with other β-AR-rich organs at late time points post-injection. The competitive blocking assay using unlabeled bisoprolol exhibited no inhibition of [18F]bisoprolol uptake in any organ but exhibited significantly rapid loss of radioactivity between two different time points in β1-AR-rich organs such as the heart and brain. Furthermore, the organ-to-blood ratio revealed the slow excretion and better accumulation of [18F]bisoprolol inside the heart. Collectively, the ex vivo biodistribution and blocking study presented insightful evidence to better comprehend the in vivo distribution pattern of bisoprolol as a selective inhibitor targeting β1-ARs in the heart and provided the possibility of PET as an in vivo technique for evaluating drug selectivity.

pH-homeostasis is crucial for maintaining a living system of cells. Lysosome, a digestive system of cells, contains a number of hydrolytic enzymes which can normally function in a narrow range of acidic pH (4.5–5.5). Abnormal pH in lysosomes leads to lysosomal dysfunction, which results in various diseases such as lysosomal storage disorders, cancer, cardiovascular diseases, and neurodegenerative diseases. We previously reported a series of reduced xanthene fluorophores including fluorescein, rhodol and rhodamine, and discovered a reduced rhodol, Rh–OMe, with a methoxy and a free amino group in a xanthene ring. In this work, a series of novel pH-sensitive fluorescent sensors for monitoring acidic lysosomes was developed by structure-pKa relationship study of Rh–OMe. Rh–OMe derivatives with various substituents in an alkoxy group on xanthene ring were designed and evaluated by the analysis of pH-titration curves and photochemical properties. Reduced rhodol probes with a para-substituted benzyloxy group showed excellent fluorescence transition triggered by acidic pH, and they were successfully applied to in vitro imaging of lysosomes in HepG2 cells.

In this study, we describe the development of a new siRNA delivery method for enhanced gene silencing, which is based on HER2 RNA aptamer- and cell penetrating peptide (CPP)-mediated intracellular delivery of multimeric antisense strands of siRNAs. By making use of HER2 RNA aptamer or peptide nucleic acid-linked CPP as delivery moiety for multimeric antisense strands of siRNAs, the multimeric siRNAs were observed to show significant gene silencing effects even without any delivery vehicles, in comparison with the conventional duplexed monomeric siRNAs mixed with lipofectamine. Our observations suggest that the introduction of RNA aptamer or CPP to multimeric siRNA as delivery moiety of siRNA delivery system can allow efficient target gene suppression with slow and steady but persistent intracellular uptake capacity.

Heat-shock protein 90 (HSP90) is a molecular chaperone that activates oncogenic transformation in several solid tumors, including lung and breast cancers. Ganetespib, a most promising candidate among several HSP90 inhibitors under clinical trials, has entered Phase III clinical trials for cancer therapy. Despite numerous evidences validating HSP90 as a target of anticancer, there are few studies on PET agents targeting oncogenic HSP90. In this study, we synthesized and biologically evaluated a novel

Enantioselective synthesis of (-)-deguelin was accomplished via an iterative pyran-ring formation approach. The key features involve the anionic addition of a chromene unit to aryloxy alkyl aldehyde for the double cyclization precursor and iterative pyran ring formation by Pd-catalyzed O-arylation and C-arylation, respectively.

Carbonic anhydrase IX is overexpressed in many solid tumors including hypoxic tumors and is a potential target for cancer therapy and diagnosis. Reported imaging agents targeting CA-IX are successful mostly in clear cell renal carcinoma as SKRC-52 and no candidate was approved yet in clinical trials for imaging of CA-IX. To validate CA-IX as a valid target for imaging of hypoxic tumor, we designed and synthesized novel [

1,3,4-Oxadiazole derivatives were found to enhance astrocyte differentiation in rat fetal neural stem cells (NSCs). Differentiation activity was assessed by immunocytochemistry and analysis of mRNA expression of astrocyte markers, GFAP and S100. Compounds 7 and 8 showed approximately a two-fold increase in astrocyte differentiation without engagement of neuronal differentiation and detectable cytotoxicity.

Highly concise asymmetric total syntheses of (+)-tetrabenazine (1), a drug for the treatment of chorea associated with Huntington's disease, and of (+)-α-dihydrotetrabenazine (2), an active metabolite of 1, have been accomplished. Our synthetic route features a trans-selective enol etherification, followed by an unprecedented cation-dependent aza-Claisen rearrangement to establish the carbon framework and two stereogenic centers of tetrabenazine. The syntheses consist of seven steps (34 % overall yield) for (+)-2 and eight steps (22 % overall yield) for (+)-1.

The first asymmetric total synthesis of fluvirucinine A(2) has been accomplished. A key feature of the synthesis is an iterative lactam ring expansion to provide rapid access to the 14-membered lactam skeleton and three stereogenic centers. The excellent remote control of the three stereogenic centers relied on stereoselective amidoalkylation followed by an amide-enolate-induced aza-Claisen rearrangement. In addition, the structure of fluvirucinine A(2) has been completely elucidated by our total synthesis.

Structural optimization of multiple H-bonding region and structure–activity relationship of diarylalkyl amides/thioamides as novel TRPV1 antagonists are described. In particular, we identified amide 34o and thioamides 35o and 35r , of which antagonistic activities were highly enhanced by an incorporation of cyano or vinyl-substituent to the multiple H-bonding region. They exhibited potent 45 Ca 2+ uptake inhibitions in rat DRG neuron with IC 50 s of 25, 32 and 28 nM, respectively.

Synthesis and biological evaluation of various colchicine analogues through the mixed-lymphocyte reaction (MLR), lymphoproliferation, and inhibitory effects on the inflammatory genes are described. In addition, a new series of immunosuppressive agents developed on the structural basis of colchicine, as well as their structure-activity relationships is reported. The most potent analogue 20a exhibited an excellent immunosuppressive activity on in vivo skin-allograft model, which is comparable to that of cyclosporin A.

The natural compound deguelin has promising preventive and therapeutic activity against diverse cancers by directly binding to heat shock protein-90 and thus suppressing its function. Potential side effects of deguelin over a certain dose, however, could be a substantial obstacle to its clinical use. To develop a derivative(s) of deguelin with reduced potential side effects, we synthesized five deguelin analogues (SH-02, SH-03, SH-09, SH-14, and SH-15) and compared them with the parent compound and each other for structural and biochemical features; solubility; and antiproliferative effects on normal, premalignant, and malignant human bronchial epithelial (HBE) and non–small-cell lung cancer (NSCLC) cell lines. Four derivatives destabilized hypoxia-inducible factor-1α as potently as did deguelin. Reverse-phase protein array (RPPA) analysis in H460 NSCLC cells revealed that deguelin and the derivatives suppressed expression of a number of proteins including heat shock protein-90 clients and proteins involved in the phosphoinositide 3-kinase/Akt pathway. One derivative, SH-14, showed several features of potential superiority for clinical use: the highest apoptotic activity; no detectable influence on Src/signal transducer and activator of transcription signaling, which can promote cancer progression and is closely related to pathogenesis of Parkinson's disease (deguelin, SH-02 and SH-03 strongly activated this signaling); better aqueous solubility; and less cytotoxicity to immortalized HBE cells (versus deguelin) at a dose (1 μmol/L) that induced apoptotic activity in most premalignant and malignant HBE and NSCLC cell lines. These collective results suggest that the novel derivative SH-14 has strong potential for cancer chemoprevention and therapy, with equivalent efficacy and lesser toxicity (versus deguelin).

In an effort to develop dual PPARalpha/gamma activators with improved therapeutic efficacy, a series of diaryl alpha-ethoxy propanoic acid compounds comprising two aryl groups linked by rigid oxime ether or isoxazoline ring were designed and synthesized and their biological activities were examined. Most of the compounds possessing an oxime ether linker were more potent PPARgamma activators than the lead PPARalpha/gamma dual agonist, tesaglitazar in vitro. Compound 18, one of the derivatives with an oxime ether linker, was found to selectively transactivate PPARgamma (EC 50 = 0.028 microM) over PPARalpha (EC 50 = 7.22 microM) in vitro and lower blood glucose in db/ db mice more than muraglitazar after oral treatment for 11 days.

The quinolone analog SQ-4004 has been identified as a potentially excellent anti-ischemic agent, which exhibited highly potent efficacy in reducing infarct volume size in vivo rat MCAO model (32.1% at 0.01mg/kg) and potent cardioprotective effect at myocardial infarction in vivo model (26.6% at 0.01mg/kg) while it exhibited highly reduced anti-bacterial activity. The mechanistic study revealed that the anti-ischemic activity might exert via an anti-apoptotic pathway, which implies its therapeutic uses against the ischemic cell injuries including ischemic stroke and ischemic heart disease.

Circadian rhythms, biological oscillations with a period of about 24 h, are maintained by an innate genetically determined time-keeping system called the molecular circadian clockwork. Despite the physiological and clinical importance of the circadian clock, development of small molecule modulators targeting the core clock machinery has only recently been initiated. BMAL1, a core clock gene, is controlled by a ROR/REV-ERB-response element (RORE)-dependent mechanism, which plays an important role in stabilizing the period of the molecular circadian clock. Therefore, we aimed to identify a novel small molecule modulator that regulates Bmal1 gene expression in RORE-dependency, thereby influencing the molecular feedback loop of the circadian clock. For this purpose, we carried out a cell-based screen of more than 1000 drug-like compounds, using a luciferase reporter driven by the proximal region of the mouse Bmal1 promoter. One compound, designated KK-S6, repressed the RORE-dependent transcriptional activity of the mBmal1 promoter and reduced endogenous BMAL1 protein expression. More importantly, KK-S6 significantly altered the amplitude of circadian oscillations of Bmal1 and Per2 promoter activities in a dose-dependent manner, but barely affected the period length. KK-S6 effectively decreased mRNA expression of metabolic genes acting downstream of REV-ERBα, Pai-1 and Citrate synthase, that contain RORE cis-element in their promoter. KK-S6 likely acts in a RORE-dependent manner by reinforcing the REV-ERBα activity, though not by the same mechanism as known REV-ERB agonists. In conclusion, the present study demonstrates that KK-S6 functions as a novel modulator of the amplitude of molecular circadian rhythms by influencing RORE-mediated BMAL1 expression.

Enantioselective synthesis of (-)-deguelin is accomplished via an iterative pyran-ring formation approach.

A series of novel STAT3 inhibitors consisting of Michael acceptor has been identified through assays of the focused in-house library. In addition, their mode of action and structural feature responsible for the STAT3 inhibition were investigated. In particular, analog 6 revealed promising STAT3 inhibitory activity in HeLa cell lines. The analog also exhibited selective inhibition of STAT3 phosphorylation without affecting STAT1 phosphorylation and cytostatic effect in human breast epithelial cells (MCF10A-ras), which supports cancer cell-specific inhibitory properties.

1-Benzoy1-1-( o -ethylphenyl)cyclopropane favors the E -indanol formation in its photochemical reaction and the selectivity is maximized in methanol. These are exactly opposite to the photochemical behavior of α-( ortho -ethylphenyl)acetophenone. Our computational studies suggest that the different stereochemical outcome of the two systems originates from the geometric difference of initially formed biradical intermediates.

Although 1-(o-tolyl)-1-benzoylcyclopropane (I) and 2-(o-tolyl)-2-benzoyloxirane (II) are structurally analogous, they go through dramatically different reaction pathways upon absorption of photons. I yields a single photoproduct, while 2H2-substituted II gives birth to three different photoproducts. The structural and kinetic features of the entire reaction intermediates have been measured with laser flash techniques. I at T1 undergoes intramolecular hydrogen transfer at 2.3 × 108 s-1 from the methyl group to the carbonyl group to form a biradical intermediate, which transforms into a cyclized photoproduct (Φ 0.14; 5 × 107 s-1). However, the carbonyl group of II at T1 can abstract a hydrogen atom from the oxiranyl ring (6 × 107 s-1) as well as from the methyl group (2.3 × 108 s-1). The biradical intermediate from the former process immediately rearranges into a photoproduct (Φ 0.025), while the one from the latter transforms into a new oxiranyl ring-opened intermediate (1.1 × 108 s-1) or a cyclized photop...

The concise and enantioselective synthesis of 15-deoxy-Δ(12,14)-prostaglandin J(2) (15d-PGJ(2)) has been accomplished in 11 steps from a known alcohol. The key step of the synthesis involves an asymmetric Rh-catalyzed cycloisomerization of ene-ynone, followed by an olefin isomerization.

Photolysis of the title compounds results in efficient hydrogen transfer reaction to produce 1,5-biradical intermediate, which does not form in the photolysis of a structurally similar compound, α-(o-tolyl)isobutyrophenone. From their kinetic studies we have measured the rearrangement rate constant of a substituted oxiranylcarbinyl radical.

We have discovered a new class of colchicine-derived therapeutic agents for immune diseases including rejection of organ-transplantation and autoimmune disease. Compound 2, which had been developed to overcome poor pharmacokinetic properties of compound 1, a first-generation colchicine analog, turned out to show toxicity such as intestinal toxicity and loss of weight during in vivo tests. The deletion of 7-carboxamide group and middle ring-truncation in colchicine allowed us to have structurally simplified analogs with strong immunosuppressive activity. Herein, we report non-alkaloid tricyclic compound 7 and 12 as immunosuppressants which exhibited a strong immunosuppressive in vivo efficacy on the T-dependent antibody response, the Zymosan A-induced arthritis model and the Carrageenan-induced edema model. Compound 7 and 12 revealed less toxicity than the previous lead compound 2, and their minimum lethal doses (MLD) were proved to exceed 100 mg/kg.

In diabetic retinopathy (DR), visual deterioration is related with retinal neovascularization and vascular hyperpermeability. Anti-vascular endothelial growth factor (VEGF) agents are currently utilized to suppress retinal neovascularization and macular edema (ME); however, there are still concerns on the widespread use of them because VEGF is a trophic factor for neuronal and endothelial cells in the retina. As an alternative treatment strategy for DR, it is logical to address hypoxia-related molecules to treat DR because the retina is in relative hypoxia as DR progresses. In this study, we demonstrate that destabilization of hypoxia-inducible factor-1α (HIF-1α) by SH-1242 and SH-1280, novel heat shock protein 90 (hsp90) inhibitors, leads to suppression of hypoxia-mediated retinal neovascularization and vascular leakage in diabetic retina. In vitro experiments showed that these inhibitors inhibited hypoxia-induced upregulation of target genes of HIF-1α and further secretion of VEGF. Furthermore, these inhibitors effectively suppressed expression of target genes of HIF-1α including vegfa in the retina of oxygen-induced retinopathy (OIR) mice. Interestingly, despite hsp90 inhibition, these inhibitors do not induce definite toxicity at the level of gene expression, cellular viability, and histologic integrity. We suggest that SH-1242 and SH-1280 can be utilized in the treatment of DR, as an alternative treatment of direct VEGF inhibition. Key message: SH-1242 and SH-1280 are novel hsp90 inhibitors similar to deguelin. HIF-1α destabilization by hsp90 inhibition leads to anti-angiogenic effects. Despite hsp90 inhibition, both inhibitors do not induce definite toxicity. HIF-1α modulation can be a safer therapeutic option than direct VEGF inhibition.

Deguelin exhibits potent apoptotic and antiangiogenic activities in a variety of transformed cells and cancer cells. Deguelin also exhibits potent tumor suppressive effects in xenograft tumor models for many human cancers. Our initial studies confirmed that deguelin disrupts ATP binding to HSP90 and consequently induces destabilization of its client proteins such as HIF-1α. Interestingly, a fluorescence probe assay revealed that deguelin and its analogues do not compete with ATP binding to the N-terminus of HSP90, unlike most HSP90 inhibitors. To determine the key parts of deguelin that contribute to its potent HSP90 inhibition, as well as its antiproliferative and antiangiogenic activities, we have established a structure-activity relationship (SAR) of deguelin. In the course of these studies, we identified a series of novel and potent HSP90 inhibitors. In particular, analogues 54 and 69, the B- and C-ring-truncated compounds, exhibited excellent antiproliferative activities with IC(50) of 140 and 490 nM in the H1299 cell line, respectively, and antiangiogenic activities in zebrafish embryos in a dose dependent manner (0.25-1.25 μM).

We have developed a new series of immunosuppressant with improved pharmacokinetic properties as the second-generation of colchicine analogs, which were designed based on the privileged structure derived from our previous work. In particular, we identified an analog ( 14 ), which exhibited a potent in vitro activity (IC 50 : 5 nM) in MLR and excellent in vivo efficacy in the Zymosan A-induced arthritis model, in the Carrageenan-induced edema model and in the local lymph node assay (LLNA). Analog 14 also revealed a good oral bioavailability ( F : 67.3%) in BALB/c mice.